System colors
The functions GetSysColor and SetSysColors can be used to access the system colors.
This is for example useful for displaying text in disabled native fill-in widgets.
Text in a disabled native fill-in is rendered in the system-color COLOR_GRAYTEXT, which is gray. The background color of a disabled fill-in is also gray (but not COLOR_GRAYTEXT) so it is difficult to read the text.
To make the text more readable you may want to change the RGB-value of the COLOR_GRAYTEXT system color.
There are several ways to change COLOR_GRAYTEXT:
You can set or modify the registry key
"HKEY_CURRENT_USER\Control Panel\Colors\GrayText"
but that will only take effect after you reboot the system.
You can also consider using the SetSysColors function to modify the RGB-value of COLOR_GRAYTEXT. The advantage is that it will take effect immediately, no need to reboot the system.
The disadvantage is that it won't be written to registry so the original value is reset after reboot. Well, actually I think this is another advantage.
What I would try to do is:
on startup of the Progress session: read the current value of COLOR_GRAYTEXT
if COLOR_GRAYTEXT is not acceptable set it to something you prefer.
on close of the Progress session: restore the original value to respect other applications.
After you call SetSysColors, Windows sends a notification message to all open windows so they can repaint themselves. This takes a little time.
Read COLOR_GRAYTEXT
{windows.i}
DEFINE VARIABLE rgbGrayText AS INTEGER NO-UNDO.
RUN GetSysColor IN hpApi (17, /* = COLOR_GRAYTEXT */
OUTPUT rgbGrayText).
set COLOR_GRAYTEXT
{windows.i}
DEFINE VARIABLE lpElements AS MEMPTR.
DEFINE VARIABLE lpRgb AS MEMPTR.
DEFINE VARIABLE ReturnValue AS INTEGER NO-UNDO.
SET-SIZE(lpElements) = 4. /* = sizeof(long) */
SET-SIZE(lpRgb) = 4.
PUT-LONG(lpElements,1) = 17. /* = COLOR_GRAYTEXT */
PUT-LONG(lpRgb,1) = RGB-VALUE(192,192,192).
RUN SetSysColors IN hpApi (1, /* = number of elements */
GET-POINTER-VALUE(lpElements),
GET-POINTER-VALUE(lpRgb),
OUTPUT ReturnValue).
SET-SIZE(lpElements) = 0.
SET-SIZE(lpRgb) = 0.
Notes
Credits to Julian Lyndon Smith who discovered the value 192,192,192. Although it is the RGB-value for a shade of gray, it will render the text in disabled native fill-in widgets black but still does little harm to other screen-elements that are coloured in COLOR_GRAYTEXT.
Notes
(May 1999).
It now appears that setting GrayText to RGB(192,192,192) makes disabled SELECTION-LIST widgets really hard to read. Don't know why it was not noticed before... perhaps it depends on Windows 98, video card or other display settings? Anyway, GrayText=RGB(192,192,192) does not seem to be a good idea anymore.
Notes
KeithGernert 19 Jan 2004: We've found that an RGB setting of 80,80,80 looks pretty good and is less destructive to other Windows controls.
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Index numbers for color elements
Where the example code references 17 for COLOR_GREYTEXT, here is a list of different values that can be used along with brief descriptions. The code can be cut and paste into an existing 4GL application with the values being referenced as {&COLOR_GREYTEXT} if the code above was to use them: